2. Chickens are one of the
many animals around us
that lay eggs.
Others are special eggs
that become chickens.
Some of these we eat.
3. This is the female chicken
called the hen.
This is the male chicken called
the cockerel or rooster.
Can you notice some differences?
For a chicken to grow inside the egg, the
hen must first be mated with the rooster.
The eggs she then lays will be fertile.
4. Chickens don’t start to grow in the egg
straight away. The egg needs to be kept
warm before the chick will start to develop.
It doesn’t look any
different from the normal
eggs we eat, does it?
This is a fertile egg opened
just after the hen has laid it.
5. At the farm the hen would
normally lay all her special
fertile eggs in the nest. She
would sit on them and keep
them warm for 21 days until
they hatched.
We have put these fertile
eggs in the incubator to keep
them warm until they hatch.
Let’s look at what happens
inside the egg over the next
21 days.
6. After only 3 days of warmth
from either mother hen or the
incubator, our fertile eggs
begins to change. Our chicken
is starting to grow.
After 6 days the beak is
starting to form and the
legs and wings are too.
Those lines are the veins
carrying nutrients to the
chicken for it to grow.
Already the heart has started to beat.
7. Over the net couple of days the chick will
absorb the yolk into its body to prepare for
the work ahead, when it begins to hatch.
At day 18 the chicken is
almost developed. The head
is in the ‘air sac’ at the end
of the egg, and it is
breathing air just like we do.
At day 9 the feathers are
even starting to develop
and the chicken is really
starting to take shape.
8. Eventually it does. It
is very tired.
It takes quite a few hours
for the chicken to hatch.
It has to work very hard to
break the shell.
The shell of the egg is
beginning to crack. The chick
is starting to hatch. This is
called ‘pipping’.
9. When the chick
hatches, it looks very
wet and soggy.
Its feathers are
covered in ‘dander’
which makes them
appear wet.
It doesn’t take long for the dander to fall
off and the chick to become fluffy.
10. The chicken uses its ‘egg
tooth’ to help break through
the shell of the egg. The
egg tooth is a hard lump on
the end of the beak.
Chickens only need the egg
tooth to help them break
out of the shell.
Once they have hatched,
the egg tooth falls off.
11. Once the chicks are fluffy
and strong, they go into a
brooder box. This box has
a light bulb in it to keep
the chicks warm.
If the chicks were
hatched in the nest,
the mother hen would
keep them warm until
they grow up.
12. Glossary of Terms
Hen
Female chicken
Rooster
Male chicken
Chick
Baby chicken
Fertile egg
Egg capable of producing a chick
Yolk
Yellow part of the egg, providing
nutrients for the chick
Air Sac
Air bubble at blunt end of the
egg
Nest
Where the hen sits to keep the
eggs warm
Incubator
Controls temperature of the
eggs
Pipping
First signs of the chick hatching
Hatch
Chick emerging from egg
Dander
Covering on down of newly-
hatched chicks
Feathers
Outer covering of chickens
Egg tooth
Hard lump on beak to break
through the shell
Brooder
House to keep chicks warm
